The Luxardo family's distillery was founded in 1821, and it produced a cherry liquor from the distilled leaves, stems, pits, and skins of the Marasca cherry itself. The family-owned business started selling candied cherries preserved in the liquor in 1905, thus inventing maraschino cherries, marketed as Luxardo cherries. In the aftermath of WWII, the Luxardo family business was nearly doomed but one family member managed to escape deep into Italy with a written recipe and a small Marasca cherry tree. At the time, Luxardo cherries had a naturally deep red color on the verge of black.
Then how did today's neon red version come about? The answer is tightly linked to another significant historical event. During the prohibition period, a horticulturist by the name of Ernest Wiegand found a way to imitate the flavor of the (originally alcohol-preserved) cherries with a mix of calcium salts and several artificial flavorings and dyes. The result was much sweeter and of much more vibrant color than the original, but was non-alcoholic and much, much cheaper to produce. Some of the materials Wiegand used are still used today in the manufacturing process of American Maraschinos.
Calcium chloride is a salty-tasting compound used for various purposes in the food industry. It is generally regarded as safe and is mainly used as a firming agent in canned vegetables. Sulfur dioxide is a gaseous compound mainly used for the preservation of dried fruits, thanks to its antimicrobial purposes. In winemaking, it is used as an antibiotic and antioxidant.